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12: Polarization

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    In this chapter, we return to (9.46)-(9.48) and examine the consequences of Maxwell’s equations in a homogeneous material for a general traveling electromagnetic plane wave. The extra complication is polarization.


    Polarization is a general feature of transverse waves in three dimensions. The general electromagnetic plane wave has two polarization states, corresponding to the two directions that the electric field can point transverse to the direction of the wave’s motion. This gives rise to much interesting physics.

    1. We introduce the idea of polarization in the transverse oscillations of a string.
    2. We discuss the general form of electromagnetic waves and describe the polarization state in terms of a complex, two-component vector, \(Z\). We compute the energy and momentum density as a function of \(Z\) and discuss the Poynting vector. We describe the varieties of possible polarization states of a plane wave: linear, circular and elliptical.
    3. We describe “unpolarized light,” and explain how to generate and manipulate polarized light with polarizers and wave plates. We discuss the rotation of the plane of linearly polarized light by optically active substances.
    4. We analyze the reflection and transmission of polarized light at an angle on a boundary between dielectrics.

    This page titled 12: Polarization is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Howard Georgi via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.